DESCRIPTION (provided by investigator): This study aims to evaluate a conceptual model that examines the role motor skill competence plays in influencing physical activity patterns of children, along with potential mediating factors of perceived motor competence and physical fitness. It also examines how these four factors relate to obesity from early through late childhood. The long term goal is to provide a scientific basis for the development and implementation of interventions to change the developmental trajectories of children who are physically inactive and obese. The specific aims are: 1) to examine the strengths of the relationship between motor skill competence and physical activity among children from early (4-5 years), to middle (7-8 years), to later (10-11 years) childhood;2) to examine the role perceived motor competence and health-related fitness play as mediating variables to physical activity and motor skill competence across the three age groups;3) to examine the relationship of motor competence, physical activity, perceived motor competence and fitness to healthy or unhealthy/obese weight status, and;4) to determine the efficacy of the overall conceptual model for children in early, middle, and late childhood, for girls and boys, and for African Americans, Hispanics, and Whites. A developmental and differential relationship between motor skill competence, physical activity, perceived motor competence and physical fitness across three age groups is hypothesized. Specifically, the relationships will strengthen across the three age groups tested. A 3 (Age) X 3 (Ethnicity/Race) X 2 (Gender) cross-sectional design will examine the relationship among the four variables in the conceptual model across three developmental windows (48-60, 84-96, and 120-132 months). Data will be collected on: a) 5 day physical activity levels using accelerometers;b) motor skill competence using the Test of Gross Motor Development 2 (Ulrich, 2000), developmental sequences for jump, hop &throw, (Clark &Phillips, 1985;Halverson &Williams, 1985;Roberton &Halverson, 1984) and product scores (e.g., velocity, distance) for jump, hop, run, kick, and throw;c) perceived motor competence using the Pictorial Scale of Perceived Competence and Social Acceptance (Harter &Pike, 1984), and the Self Perception Profile for Children (Harter, 1982, 1985);d) health-related fitness using the FITNESSGRAM to measure upper body muscular strength, leg strength and power, upper body muscular endurance, and abdominal strength/endurance (Baumgartner &Jackson, 2003;Meredith &Welk, 2005);and e) body composition using percent body fat (as measured by skinfolds) and estimated by body mass index. A series of structural equation models for the three ages, three ethnicities and two genders will examine the strength and the directionality of the relationships among the variables in the conceptual model. These data will serve as the foundation for future physical activity interventions. PUBLIC HEALTH RELEVANCE: Physical inactivity in children is a major public health risk factor and a health objective for the nation. This study aims to investigate how competence in motor skills, perceptions of motor competence, and fitness influence a child's physical activity patterns and obesity status. The long term goal of this work is to provide a greater understanding of the mechanisms influencing physical activity to develop and implement effective programs to promote children's physical activity.